1. Field of the Invention
The present invention relates to a rotary clicking electronic component used in rotating sections of various electronic equipment.
2. Background Art
A rotary clicking electronic component provided with a clicking function that makes it easy to sense the amount of rotational operation is widely employed as a rotary electronic component used for setting the conditions or adjusting the output of various electronic equipment.
As a conventional rotary clicking electronic component disclosed in Unexamined Japanese Patent Publication No. 2006-79966 and Unexamined Japanese Patent Publication No. 2005-302354, a rotary clicking composite switch will be described with reference to FIG. 12 to FIG. 19.
FIG. 12 is a sectional view of a conventional rotary clicking composite switch. FIG. 13 is a top view of the case thereof. FIG. 14 is a top view of the rotary body thereof. FIG. 15 is a top view of the slide thereof. FIG. 16 is an explanatory view of the operation shaft and the driving means thereof. FIG. 17 is a top view of the clicking plate thereof. FIG. 18 is a side sectional view of the clicking plate. FIG. 19 is a sectional view of the operation shaft in a state of being pressed down.
In FIG. 12 and FIG. 13, the inside of the opening of case 1 made of insulating resin having a shape like a box opening at the top thereof is, as shown in FIG. 13, separated by annular protrusion 1A into inside opening 1B and outside opening 1C. At the inner bottom of inside opening 1B, there are provided middle contact 2 at the center and two outside contacts 3 at the outsides with the middle contact 2 therebetween. At the inner bottom of outside opening 1C, there are provided common contact 4 as a fixed conductor, first signal contact 5, and second signal contact 6 on same circumference which are electrically independent of each other. And, switch terminals 2A, 3A, 4A, 5A, 6A are individually connected to middle contact 2, outside contact 3, common contact 4, first signal contact 5, and second signal contact 6 respectively. Switch terminals 2A, 3A are led out of one side wall of case 1, and switch terminals 4A, 5A, 6A are led out of the side wall opposite to the side wall from which switch terminals 2A, 3A are led out.
As shown in FIG. 12, as to movable contact 7 formed of a circular dome-like elastic thin metal sheet which is convexly shaped upward, the bottom end of the outer periphery thereof is placed on outside contact 3, and the underside of the dome-like top is opposed to middle contact 2 with a space therebetween. Also, on the upper surface of the dome-like peak of movable contact 7 is placed disk-like push plate 8 made of insulating resin having push-portion 8A protruded at the bottom center, and a push-on switch is configured by middle contact 2, outside contact 3, and movable contact 7.
Rotary body 9 made of insulating resin shown in FIG. 12 and FIG. 14 includes columnar portion 9B having through-hole 9A grooved in the middle thereof and flange 9C below columnar portion 9B. On the upper surface of flange 9C is radially disposed linear convex-concave portion 9D along the diametrical direction, and on the underside thereof is disposed slide 10 as a movable conductor shown in FIG. 15. Slide 10 is formed of a conductive metal sheet and has a shape formed of annular flat plate 10A fixed on rotary body 9 and sliders 10B disposed at four portions every 90 deg at equal angles therefrom. As rotary body 9 is rotated, each slider 10B makes a sliding motion while moving on and off the common contact 4, first signal contact 5, and second signal contact 6 disposed on the inner bottom surface of outside opening 1C of case 1 thereunder.
Bearing 11 shown in FIG. 12 is placed in such manner that the upper part of the opening of case 1 is covered with collar 11A, which is provided with hollow cylindrical portion 11B protruding upward from the center of collar 11A and having central hole 11C. Columnar portion 9B of rotary body 9 is rotatably fitted in cylindrical portion 11B.
Nearly bar-like shaft 12 shown in FIG. 12 has a shape such that each of operational portion 12A positioned at the top, columnar middle portion 12B, and nearly oval mount 12C at the bottom has a shouldered portion. And, operational portion 12A is positioned above bearing 11, the upper part of columnar middle portion 12B is rotatably and vertically movably fitted in central hole 11C of bearing 11, and the lower part under middle portion 12B is positioned in through-hole 9A of rotary body 9. On the mount 12C at the bottom is fitted and fixed driving means 13 in such manner as to move along with the rotational and vertical movement of operation shaft 12.
Driving means 13 shown in FIG. 12 includes, as shown in FIG. 16, oval inner hole 13A in which the mount 12C of operation shaft 12 is fitted, and also, there are provided protrusions 13B extending from the columnar outer periphery in four directions at equal angles. The four protrusions 13B engage the four grooves 9E (see FIG. 14) disposed in through-hole 9A of rotary body 9. Also, the lower end of mount 12C of operation shaft 12 is in contact with the upper surface of push plate 8 placed on movable contact 7.
And, as shown in FIG. 12, annular plate spring 14 (click plate) formed of elastic metal sheet is fitted to the underside of collar 11A of bearing 11. As to plate spring 14, as shown in FIG. 17 and FIG. 18, the both sides are obliquely bent downward, and bend protrusion 14A is disposed on one end of the bent portion. Bend protrusion 14A of plate spring 14 resiliently engages convex-concave portion 9D provided on the upper surface of flange 9C of rotary body 9. And, bracket 15 shown in FIG. 12 is disposed on the upper surface of collar 11A of bearing 11, letting cylindrical portion 11B of bearing 11 protrude upward, and its lower end at each side is bent so as to hold the case 1 from both sides, thereby combining each of the above members.
Here, in the standard state of FIG. 12 without operating the operation shaft 12, an activating force is applied to operation shaft 12 upward from movable contact 7 via push-plate 8. Accordingly, four protrusions 13B of driving means 13 fixed on mount 12C of operation shaft 12 are in a state of being stationary in corresponding four grooves 9E in through-hole 9A of rotary body 9. Also, rotary body 9 is always activated downward by the spring pressure of plate spring 14 being in resilient contact with convex-concave portion 9D at the upper surface of flange 9C even when the elastic force of slider 10B thereunder or the activating force of movable contact 7 is applied thereto. Accordingly, it is configured in that the lower peripheral edge of flange 9C is in contact with outer periphery shoulder 1D disposed on the outer periphery wall of the opening of case 1, which is therefore rotatable but not movable up and down.
In a rotary clicking composite switch having such a configuration, when operational portion 12A of operation shaft 12 is rotated, driving means 13 fitted on the mount 12C rotates and rotary body 9 stopped by protrusions 13B of driving means 13 rotates as well. Due to the rotation of rotary body 9, four sliders 10B of slide 10 under flange 9C sequentially slide on common contact 4, first signal contact 5, and second signal contact 6 which are disposed in outside opening 1C of case 1. In this way, the on-off operation between common contact 4 and first signal contact 5 via slider 10B causes the generation of first pulse signal from corresponding switch terminals 4A and 5A. Similarly, the on-off operation between common contact 4 and second signal contact 6 via slider 10B causes the generation of second pulse signal from corresponding switch terminals 4A and 6A. Also, clicking is sensible as bend protrusion 14A of plate spring 14 resiliently slides on convex-concave portion 9D at the upper surface of flange 9C of rotary body 9.
Next, when operational portion 12A of operation shaft 12 is pushed down, as shown in FIG. 19, push-plate 8 is pushed downward by the lower end of mount 12C thereunder. As a result, the dome-like peak portion of movable contact 7 is pushed by push-portion 8A of push-plate 8, then the dome-like peak portion is resiliently deformed, and the underside thereof comes in contact with middle contact 2 opposed thereto. In this way, the switch is turned on, conducting between middle contact 2 and outside contact 3 via movable contact 7, that is, between switch terminals 2A and 3A.
In this case, driving means 13 fixed on operation shaft 12 disengages from rotary body 9 of protrusion 13B and moves downward, and then the downward movement is not transferred to rotary body 9.
And, when the pushing force to operation shaft 12 is released, movable contact 7 is restored to its initial dome-like shape by its own resiliently restoring force. At the same time, movable contact 7 pushes up the lower end of mount 12C of operation shaft 12 via push-plate 8, then the push-on switch insulated between middle contact 2 and outside contact 3 is shifted back to the state shown in FIG. 12.
Recently, a rotary clicking electronic component used in AV equipment for vehicles in particular is required to be intensified in clicking and especially desired to be durable without deterioration of smooth clicking even in case of repeating the rotating operation, and also there is a demand for those capable of creating a rhythmical clicking sound as well as clicks sensible to the finger.
However, the conventional rotary clicking composite switch as a rotary clicking electronic component is configured in that bend protrusions 14A disposed at the end of plate spring 14 made of metal resiliently slide on convex-concave portion 9D of rotary body 9 mad of insulating resin in order to generate clicks. Accordingly, when the rotating operation is repeated for a long period of time, convex-concave portion 9D of rotary body 9 wears out and the shoulders of convex-concave portion 9D are deteriorated, causing the intensity of clicking weakens. Also, the conventional clicking mechanism using plate spring 14 made of metal and rotary body 9 made of insulating resin involves such a problem that it is difficult to create a rhythmical clicking sound.